Improved estimation of portfolio value‐at‐risk under copula models with mixed marginals

Portfolio value‐at‐risk (PVAR) is widely used in practice, but recent criticisms have focused on risks arising from biased PVAR estimates due to model specification errors and other problems. The PVAR estimation method proposed in this article combines generalized Pareto distribution tails with the empirical density function to model the marginal distributions for each asset in the portfolio, and a copula model is used to form a joint distribution from the fitted marginals. The copula–mixed distribution (CMX) approach converges in probability to the true marginal return distribution but is based on weaker assumptions that may be appropriate for the returns data found in practice. CMX is used to estimate the joint distribution of log returns for the Taiwan Stock Exchange (TSE) index and the associated futures contracts on SGX and TAIFEX. The PVAR estimates for various hedge portfolios are computed from the fitted CMX model, and backtesting diagnostics indicate that CMX outperforms the alternative PVAR estimators. © 2006 Wiley Periodicals, Inc. Jrl Fut Mark 26:997–1018, 2006     

中间选民理论在农民工市民化政策制定中的运用——基武汉市436位农民工的实证研究

The Median Voter Theory is an important theory in the neo-political economics. It can be applied to solve the collective choice paradox and analyze the policy making for the citizenization of peasant workers. Adopting the method of factor analysis, this paper makes an empirical study on peasant workers’ preference for citizenization. We find that there is a paradox of future residence preference and self-identification in peasant workers. On this basis, peasant workers are divided into 5 subgroups, and it is found that the median undecided peasant workers are the median voters. Based on the analysis of the median undecided peasant worker’s complaints and appeals, it is proposed that the country should strengthen the vocational training system, establish a social security system, expand the agricultural reform and promote educational reform to facilitate the citizenization of peasant workers. __________ Translated from Guanli Shijie 맜理世界 (Management World), 2007, (4): 40–67     

基于因子分析的我国区域研发能力差异比较研究

由于经济、科技发展水平不同,我国各地区在研发能力上存在较大的差异.为了对我国区域研发能力差异进行定量化分析,本文引入了研发投入强度、研发经费相对规模、研发人员相对规模、主要检索工具收录论文相对数量、授权专利相对数量、技术市场相对规模、新产品产值相对规模等指标,根据(2006年中国科技统计年鉴>提供的数据,通过因子分析,对我国各省区研发能力差异进行比较评价.     

浅谈精细管理在中国企业发展中的重要性

随着科技的进步、社会的发展，当前中国企业发展的关键是要进行精细管理，它已经是中国企业发展的必然前提。由于市场竞争的加剧，中国企业正逐渐从粗放型管理向精细管理转变。这是中国企业发展的一大进步。只有搞好精细管理，才能促使企业内部改革的进一步深化，保证企业更快更好的向前发展。     

基于适应性商务智能的虚拟企业合作伙伴选择模型

合作伙伴选择是虚拟企业运行中至关重要的问题。迅速而准确地找到合适的合作伙伴并实现协调运作，直接影响到虚拟企业合作绩效和整体目标的实现。文章将环境感知和适应性商务智能理论引入虚拟企业合作伙伴选择中，提出了基于适应性商务智能的虚拟企业合作伙伴选择模型，设计了模型的基本架构，分析了模型的构成模块，探讨了模型的应用机理。     

中国改革开放以后地方税制度的改革

改革开放以前，中国实行高度集中的经济、财政、税收管理体制，税收的归属随着财政、税收管理体制的变化频繁调整，没有形成完整的地方税制度。改革开放以后，中国开始解决经济、财政、税收管理体制过于集中的问题，逐步调整中央与地方的财政、税收分配关系，并从1994年起将上述分配关系初步纳入分税制的轨道，建立了由中央税、地方税、中央与地方共享税构成的分税制财政管理体制，比较完整的地方税制度由此初步形成。     

对企业价值链数字化管理的探讨

新的竞争环境催生价值链管理一新的管理模式,而价值链管理离不开信息技术的支持。本文探讨了实施价值链数字化管理的意义及实施方案,阐明了企业的实施策略。